1. Technical Field
The present invention relates to a mobile communication system, and more particularly, to a method for data traffic offloading in a mobile communication system supporting a multi-radio access technology (RAT) and an apparatus using the method.
2. Discussion of the Related Art
A multi-radio access technology (RAT) network is a wireless communication environment in which two or more heterogeneous networks exist and a mobile station can perform communication by accessing the two or more heterogeneous networks. Herein, the mobile station capable of performing communication with the two or more heterogeneous networks is called a multi-RAT advanced mobile station (AMS) or a multi-system AMS.
Comparing with a specific network, the heterogeneous network (or heterogeneous system) is a network which uses a communication mechanism different from that used in the specific network. Examples of the heterogeneous network include a WiMAX network which is one example of a cellular network and a WiFi network which is one example of a wireless local area network (WLAN).
The RAT is a technical type used in radio access. For example, the RAT may include GSM/EDGE radio access network (GERAN), UMTS terrestrial radio access network (UTRAN), evolved-UMTS terrestrial radio access network (E-UTRAN), WiMAX, LTE (-A), WiFi, etc. That is, the GERAN, the UTRAN, the E-UTRAN, the WiMAX and/or the WiFi coexist in the same region.
The multi-RAT increases a peak throughput, and enables off-loading between heterogeneous networks.